Film, filament, fiber, or other shaped article made by hardening proteins coagulatedfrom their solutions



PatentedMay 2, 1M4

UNITED PATENT OFFICE 2,347,577 FILM, FILAMENT, FIBER, on ornaa SHAPED ARTICLE MADE HARDENING PRO- TEINS COAGULATED FROM THEIR SOLU- TION S No Drawing. Application March 20, 1939, Serial No. 263,094. In Great Britain March 21, 1938 6 Claims.

This invention relates to shaped articles made from vegetable globulins; and it comprises a method of improving filaments, fibers, threads, and other shaped articles such as films, sheets and the like made from vegetable globulins, and particularly from peanut globulin, wherein the article is rendered more resistant to weak acid liquors, such as those used in dyeing wool with acid dyes, by a treatment with an aqueous bath containing a hydrogen halide in the presence of a saline halide, this treatment being eflected simultaneously with or subsequently to a treatment of the shaped article with a hardening or strengthening agent, usually an aldehyde; and it also comprises, as a new manufacture, fibers of the general character of wool and as resistant to acid wool-dyeing baths, said fibers being capable of dyeing in the same baths and with the same results as wool, and in admixture with wool giving level, dyeing; all as more fully hereinafter set forth and as claimed.

In the invention of a prior and copending application Serial No. 104,338 (Chibnall & Bailey) whereon the present invention represents an improvement, a vegetable globulin is brought into a viscous aqueous solution with urea or some other denaturing agent and extruded to 'form fibers partaking of the nature of wool. Other shaped articles may be similarly formed. Ex-

- trusion is into an acid aqueous bath capable of removing the urea and regenerating or coagulating the globulin as a fiber of useful physical properties. The fiber or other shaped article is afterwards treated with formaldehyde or another aldehyde to harden or strengthen it. The extruded fibers are more or less keratinoid in character and require this hardening treatment to improve their resistance to wet-processing.

Fibers and other materials produced in this way from vegetable globulins such as peanut protein, castor seed protein, edestin, etc., have unique, valuable and desirable characteristics. But they are not as resistant to hot water as is desirable, nor yet to the effect of the hot dilute acid solutions used in dyeing wool, even after the aldehyde hardening. If the artificial wool produced as described is woven and dyed in admixture with natural wool, the dyeing may not be level. It is also difficult to process and dye these artificial fibers alone.

In the present invention shaped vegetable globulin articles, and particularly wool-like fibers made from peanut globulin, are made more resistant to hot water and to dilute acid solutions.

In so doing, the article is treated with a hydrogen halide, advantageously HCl, contained in a concentrated aqueous solution of a saline halide, such as sodium chloride. On removal from the treating bath, washing, etc., the fiber is found to be rendered resistant to hot water and dilute acid baths, such as are used in dyeing with wool dyes, and capable of level dyeing in admixture with wool.

It has been proposed in a copending application of Trail], Serial No. 209,854, to treat such shaped articles of hardened regenerated vegetable globulin with HCl and substances hydrolyzable to yield HCl, in non-aqueous media, to improve the resistance of the articles to acid dye baths, etc. This treatment was proposed, as stated, for application in a non-aqueous medium, such as a gas or an organic solvent; and it was to be applied after the hardening or strengthening treatment with formaldehyde or its equivalents. the present invention is applied in an aqueous medium, which is much more convenient and economical. It also makes possible the combination of the treatment to improve acid resistance, and the hardening treatment, thus eliminating a step in the process. Furthermore, the present invention leads to better results from a technical standpoint.

Shaped articles of unhardened denatured vegetable globulins swell in water, but in concentrated saline solutions the swelling is prevented. We have found that when dissolved in an aqueous saline solution of certain halides oi sumcient concentration to prevent swelling of the denatured vegetable globulin shaped articles, a small concentration of hydrogen halide (advantageously HCl) renders the hardened protein resistant to the destructive action of dilute acid solutions such as are used in wool dyeing and also to the action of hot water, and according to our invention we treat the shaped articles with an aqueous saline hydrogen halide bath for a period of time.

The treatment with the dilute solution of hydrogen halide in the concentrated saline solution may be applied to the protein previously hardened by means of formaldehyde or'the like, or may, as stated, be combined with the hardening treatment by employing a saline bath containing both" the hydrochloric acid and the formaldehyde or the like and applied to an unhardened protein. The most convenient hydi'o gen halide is hydrochloric acid but hydrobromic acid may also be used.

The saline component of the solution is chosen from the freely soluble halides of the alkali and In contradistinction, the treatment of alkaline earth meta-ls, ammonium, and magnesium. Advantageously the bath contains not less than about 30 parts of the anhydrous salt dissolved in 100 parts water, since in lower concentrations there is a tendency for filaments and fibers to stick together on drying after removal from the bath and washing.

It is convenient to use a substantially saturated solution or even to have some undissolved saline halide present in the bath. The hydrogen halide may be added in aqueous solution, e. g., the commercial concentrated acid; or it may be liberated from the salt by addition of a suitable proportion of a strong mineral -acid preferably sulphuric acid. The proportion of hydrogen halide present in the bath need not exceed 2%, and is preferably between .5% and 1.5% by weight.

The treatment is best carried out at raised temperatures, e. g., at temperatures up to 60 C., preferably 35 C. to 50 C. It may be applied in more than one stage; for instance, a treatment at 30 C. may be followed by a treatment at 60 C. Where high temperatures are employed in the treatment, however, initial treatment at a lower temperature is advisable.

It will be understood that the treatment at raised temperatures need not be carried out for so long a period as at lower temperatures.

After removal from the treatment bath the articles should be thoroughly washed with water. For textile and certain other purposes, however, it is desirable that the article should be left in a less acid condition than can be achieved by washing with water alone; and it is convenient, after a preliminary washing with water, further to treat the article with a weakly alkaline solution, for instance one of sodium carbonate, bicarbonate, or sesquicarbonate, borax or the like. This is especially desirable when the filaments are to be mixed with wool, since the mixed yarns so obtained can be dyed to a level shade in one process with. ordinary wool acid dyes, and if desired in the piece, after Weaving.

After the dilute alkaline treatment and subsequent washing the fiber or filament should yield a solution of pH 7 to 8 when boiled with water.

If the hardening treatment is combined with the aqueous saline hydrogen halide treatment, there may be used as hardening agent, forinstance, formaldehyde, paraformaldehyde, para-aldehyde, acetaldehyde, buta-aldehyde, croton-aldehyde, aldol, hexamethylene-tetramine, or the like aldehydic compounds.

The invention is further illustrated by the following examples, in which the parts mentioned are, unless otherwise stated, parts by weight.

Example 1 The filaments are made from protein extracted from peanuts by an alkaline solution and precipitated, as described in the copending application of another (Mcl lean Serial No. 254,741, filed February 4, 1939; corresponding to British application'4882/ 38) As there described, globulin is obtained by extracting substantially oil-free peanut meal with a feebly alkaline solution, having a pH around 8. A .caustic soda solution or a solution of sodium sulphide may be used, and in, either event globulin may be precipitated by an introduction of S02. The precipitated globulin is washed and dried and is then dissolved in a concentrated aqueous urea solution," and, after being aged, the solution is spun as described in application Serial No. 104,338; the coagulated and washed filaments then being treated with formaldehyde solution and dried.

The filaments are then treated with 50 times their weight of a solution made by dissolving two parts by volume of 35% hydrochloric acid in a hundred parts by volume of saturated common salt solution. The treatment is carried out for one day at 35 C., after which the filaments are washed in water, neutralised with 0.5% sodium carbonate, and dried. In this Example the saturated solution of common salt may be replaced if desired by saturated solutions of ammonium chloride, potassium chloride, magnesium chloride, or calcium chloride.

Example 2 Example 3 The filaments are produced as in Example 1, and are treated with 15 times their weight of a bath having the following composition:

Parts 38% aqueous formaldehyde 12% 35% aqueous hydrochloric acid 4 Common salt 36 Water -i 87 The treatment is carried on for one day at 35 C. The treated filaments are washed with cold water, and neutralised, and are then dried in a current of warm air. v

Articles treated according to' the preceding examples are found to be practically unaffected by treatment in a bath containing 0.1%- sulphuric acid and 0.25% sodium sulphate for 90 mins. at 97 0.; whereas the filaments produced according to the examples, when hardened with formaldehyde without further treatment with the hydrogen halide and metallic halide solution, are much swollen or partly dissolved when similarly heated.

Example 4 A solution of 23 parts peanut protein and 30 parts of urea in 70 parts of water matured for one day at 20 C. is spun into filaments and coagulated in a bath containing 4% sulphuric acid and 35% sodium sulphate decahydrate at 28 C. The coagulated fibers are rinsed in water and stored at ordinary temperature immersed in saturated common salt solution until required.

For treatment, the fibers'are cut into staple lengths and heated for 1 day at 35 C. in 25 times their weight of a solution consisting of 36 lbs. common salt, 2 lbs. commercial 40% formaldehyde solution, and 4 lbs. 35% hydrochloric acid solution, all dissolved in 9 gallons of water.

After treatment, the fibers are washed and centrifuged, and soaked in a dilute suspension of sodium cetyl sulphate and their residual acidity is removed by the action of 25 times their weight of 0.5% washing soda solution at room temperature for about 20 minutes. The fibers are washed, centrifuged and dried at about 40 C. in a current of air.

When tested for resistance to wet processing in acid dye-bath liquors by treatment for 90 minutes at 97 C. with a bath containing 0.1% sulphuric acid and 0.25% sodium sulphate, and subsequently dried, the fibers retain their original soft handle, and are free from sticking.

Example Spun fibers of peanut protein are treated as in Example 4, except that the treatment iscarried out for 6 hours at 50C. The finished fibers are satisfactorily resistant to wet-processing.

Example 6 Spun fibers of peanut protein are treated as in Example 4, except that the 36' lb. common salt are replaced by 70 lbrcalcium chloride.

Example 7 Spun fibers of peanut protein are treated as in Example 4, except that the treating bath consists of a saturated solution of ammonium chloride to which has been added 5% of its weight of 35% hydrochloric acid solution and 1% of its weight of 40% formaldehyde solution.

Example -8 Fibers are spun and coagulated as described in Example 4, and are hardened overnight in 30% formaldehyde solution at ordinary te p ture. The fibers are then washed with distilled water, followed by acetone, and dried at a temperature not exceeding 25 C.

One portion of the fiber so obtained is tested by the wet-processing method described in Example 4. This sample is damaged by this treat ment.

Another portion, either in hank form or as cut staple, is treated for 2 days at 35 C. in saturated common salt solution containing 2% of its weight of 35% hydrochloric acid solution; washed in water, and dried at 30 C. This sample is undamaged by the wet-processing test described in Example 4.

Example 9 Fibers spun and coagulated as described in Example 4 are treated as described in Example 8, except that the treating solution contains 4% of its weight of 35% hydrochloric acid and the treat ment occupies one day only.

Example 10 The treatment as described in Example 8 is carried out with a solution of 2 parts 35% hydrochloric acid in 100 parts of a saturated solution.

of any of the following salts: potassium chloride, lithium chloride, magnesium chloride, calcium chloride, strantium chloride, barium chloride, potassium bromide, potassium iodide.

The present invention represents an improvement in the art in that it enables globulin fibers to be used in admixture with natural wool to obtain level dyeings with very many wool dyes. In admixture the improved woolly fiber and ordinary wool dye alike and dyeing and wfishing can be effected without damage to either fiber.

Examples of dyestuffs with which composite textiles manufactured from wool and neutralised hardened fibers made by the treatment of de natured vegetable globulin according to our invention can be dyed to level shades include Coomassie Navy Blue 2RNS, Solochrome Brown MSS, Solway Blue Black BS, Solway Green GS.

As many apparently widely difierent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

We claim:

1. A process which comprises treating articles formed from denatured vegetable globulin with an aqueous saline halide bath containing at least 30 parts of saline halide to 100 parts water and containing a minor amount of a hydrogen halide selected from the class consisting of hydrogen chloride and hydrogen bromide, and treating the article with a hardening agent at a stage of operations not later than treatment of the article in said bath.

2. A process -as claimed in claim 1 in which the saline component is a member of the class which consists of the chlorides of the alkall'metals, the alkaline earth metals, ammonium and magnesium.

3. The process of claim 1" wherein the article is treated with a hardening agent present in the halide bath.

4. Process as claimed in claim 1 in which the concentration of hydrogen halide lies between 0.5% and 1.5%.

5. Process as in claim 1 in which the treatment is efiected at a temperature between C. and C.

6. The process of claim 1 wherein the article is treated with the hardening agent prior to introduction into the halide bath.

ERIC CECIL FIELDSEND. WILIJAM H. D. BOYES. 

